U.S. Pat. No. 4,661,429 to Molaire and Farid describes a photoelectrographic element including an acid photogenerating layer useful in electrography. Materials constructed according to that patent when exposed to relatively high intensity radiation of a particular wavelength become conductive in an electrographic sense. That is, they change their ability to hold an electrostatic charge. This characteristic is generally permanent until the material has been exposed to heat, after which the material can be reused. Other materials are known, for example, certain photocrosslinkable materials, which become less conductive when irradiated.
This persistent change in conductivity allows these materials to be used in electrography as xeroprinting masters. That is, after a persistent conductivity image has been created by exposure, it can be charged and toned to create a toner image and the toner image can be utilized, for example, by transferring to a receiving sheet. With a single conductivity image a number of prints can be made.
Once the conductivity image is formed, the materials are capable of high speed xeroprinting with excellent resolution and gradation. However, a problem with utilization of such materials in high quality and high quantity imaging is that actual formation of the original xeroprinting image requires substantial exposure. To do high quality prints, for example using a common laser printer, creation of a single conductivity image would take an inordinate amount of time.
U.S. Pat. No. 4,429,027 to Chambers et al suggests forming a mask electrophotographically or magnetically and transferring the mask to photosensitive layers for imagewise exposing of those layers in order to produce printing plates, printing circuits, solder masks, color prints, transparencies, etc.
U.S. Pat. No. 3,615,128 is representative of a number of references which show a single apparatus which provides a xeroprinting master electrophotographically and uses it to make prints.